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Triggering – HP E1418A User Manual

Page 55

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Triggering

To synchronize outputs to external events, backplane events, or software
events use the

TRIGger

subsystem commands. Triggering an output from

the module involves four steps:

1. Set the trigger source.
2. Set one or more channels for triggered output.
3. Put the trigger system in the wait-for-trigger state.
4. Send the trigger event.

The

TRIGger:SOURce <

source

>

command sets the trigger source. One of

four trigger sources can be specified.

VXIbus backplane trigger — one of the eight TTL trigger lines
defined in the VXIbus P2 connector. The lines are named
*TTLTRG0 through *TTLTRG7. Any one of these trigger lines
may be used as a trigger source.

Software trigger — generated within the controlling program.

Immediate trigger — places the trigger system in the wait-for-trigger
state and then immediately triggers the output.

External Trigger — an input on the terminal module (see page 35).
Use this source to synchronize the outputs to an external event.

The

SOURce

n

:VOLTage[:LEVel]:TRIGgered[:AMPLitude]

and

SOURce

n

:CURRent[:LEVel]:TRIGgered[:AMPLitude]

commands program a

channel output value when the trigger conditions are met.

The

INITiate:IMMediate

command places the trigger system in the

wait-for-trigger state. The trigger event depends upon the trigger source set.

The trigger system is common to all channels in the module. That is, a
single trigger event triggers the output on all channels that are waiting for
the trigger. The

SOURce

subsystem contains commands to put each

channel in the wait-for-trigger state.

/* Set the trigger source for software trigger */

TRIGger:SOURce HOLD

/* Set channels 1 and 2 for triggered output */

SOURce1:VOLTage:TRIGgered 1.5000

SOURce2:VOLTage:TRIGgered -2.5000

/* Close the output relays */

OUTPut1 ON

OUTPut2 ON

/* Put the trigger system in the wait-for-trigger state */

54 Programming Examples

Chapter 2

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